Insecticide Toxicologu

Question 1

How did DDT act on insects?

Answer 1

Interferes with sodium channel in activation of insect nerves.

Question 2

Do carbamates in insects target the synapse, neuron or axon?

Answer 2

Do carbamates in insects target the synapse, neuron or axon?

Question 3

What effects do the following neurotransmitters have in insect CNS (inhibitory or excitatory)?

1. ACh
2. Glutamate
3. GABA

Answer 3

1. Excitatory (same as humans)
2. Inhibitory (different from humans)
3. Inhibitory (same as humans)

Question 4

What are transgenic crops? How do they apply to insecticides?

Answer 4

Crops with transplanted genes that produce insecticidal compounds.
E.g. ∂-endotoxin from Bacillus Thurigenesis

Question 5

Pyrethrum is isolated from which flower?

Answer 5

Chrysanthemum

Question 6

What effects do the following neurotransmitters have in insect PeriphNS (inhibitory or excitatory)?

1. Glutamate
2. GABA

Answer 6

1. Excitatory

2. Inhibitory

Question 7

An insect dosed with pyrethroid has what effects on the h and m gate?

Answer 7

Slowing effects.

Question 8

Do Pyrethrins/Pyrethroids in insects target the synapse, neuron or axon?

Answer 8

Neuron and axon.

Question 9

What is the safety factor used for insecticides?

Answer 9

LD50 [Rats] / LD50 [insects]

Question 10

What is the treatment of organophosphate poisoning?

Answer 10

Atropine. Blocks M receptor, relieves parasympathetic symptoms.

Question 11

What is the difference between a Pyrethrin and a Pyrethroid?

Answer 11

Pyrethroids are synthetic.

Question 12

What are the types of resistance that can develop in insects?

Answer 12

Metabolic
Target-site insensitivity
Penetration resistance

Question 13

Do organochlorines in insects target the synapse, neuron or axon?

Answer 13

The neuron and axon.

Question 14

Baculoviruses have an upside and downside of what?

Answer 14

Upside: High specificity

Downside: Long kill time. The insect could have already eaten the plant before it finally dies from exposure.

Question 15

Why are mammals safe from pyrethrins?

Answer 15

No bioaccumulation because it is easily hydrolysed by cholinesterases.

Question 16

DDT was what type of insecticide?

Answer 16

Organochlorine.

Question 17

Do organophosphates in insects target the synapse, neuron or axon?

Answer 17

Synapse.

Question 18

Which neuroactive insecticides make up the biggest market share of insecticides?

Answer 18

Pyrethroids.

Question 19

The ideal insecticide has what characteristics?

Answer 19

1. Effective
2. Selective
3. Non-persistent
4. Affordable
5. Effective in resistant strains
6. Usage does not tend to lead to resistance.

Question 20

There are four generations of pyrethroids, which are photounstable.

Answer 20

1st and 2nd.

Question 21

Why does insect resistance tend to occur with pesticides?

Answer 21

Long term use.
Few chemicals to choose from.
Restricted number of nervous system targets.

Question 22

What are transgenic crops? How do they apply to insecticides?

Answer 22

Crops with transplanted genes that produce insecticidal compounds.
E.g. ∂-endotoxin from Bacillus Thurigenesis